1. Field of the Invention
The present invention relates to acoustics and to a test apparatus for acoustically testing an undersea vehicle located in a flooded structure while providing the vehicle with high-pressure steam. More particularly, the present invention provides a system for isolating acoustic energy generated by the steam pipe from the structure and the surrounding fluid.
2. Brief Description of the Prior Art
Large testing structures are often used for military testing. For example, the acoustic measurement of noise caused by torpedo drive train systems is sometimes measured in large fluid filled structures into which the torpedo may be mounted and tested. During one such acoustic measurement, high pressure steam is used to power the torpedo drive train. The steam is transported from a steam generation source, through the testing structure's wall and then to the object or vehicle which is the focus of the test. In order to accurately measure noises generated by the vehicle only, vibration of the steam supply pipe must be isolated. Such vibration is caused by turbulent flow within the pipe, and may skew accuracy of acoustic measurements if allowed to effect the testing structure. Vibration isolation problems are presented by both the structure's wall and the fluid within the interior of the structure.
The prior art discloses various means for insulating pipes and tubing against the transmission of sound, heat or other forms of energy. However, the prior art does not provide for isolating the noise from the high-pressure steam traveling down the steam supply pipe from the fluid surrounding it to allow meaningful noise measurements of a vehicle under test.